Yamaha WR / YZ 400/426/450 engine rebuild

Refer to manual for torque specs.

[@tomatoknuckles]

That transmission is an absolute ball ache to get in but got a better idea how to do it now thanks to this. Thanks.

[@pporter1715]

Great video. I gave the damdest time with the trans.👊

[@livanolimanolania4340]

Nice videos, very helpful btw is that a 2003-2005 machine? It has some differences from mine which is a 2008 model.

[@livanolimanolania4340]

To remove the excess silicone j just put some thinner and wipe it out very easy

[@watermelonwatermelon6513]

wow the gearbox is so tiny for such a powerful bike

[@TheSnowWolf1000]

whats really crazy are the thin lose gears in the clutch side of the case

[@janjakus3596]

Great video man! I am rebulding my yz450f and have a problem with checking the gears, on 7:07 you can easily go to the every gear. On my engine shift drum is like stuck in gear, when I try to spin/wigle everything I hardly succeed to click in neutral or 2nd gear. Than when I want to go back in 1st or 3rd it is again almost impossible to change. I bought the OEM new shift forks and shift drum and the problem did not go away. Do you or anybody mybe knows what a hell is going on?

[@janjakus3596]

@Charles Alves I split the engine cases again...put some lithium grease on shift forks and in furrows of the shift drum, check all details 3 times, chcked every bolt 3 times with torq wrench. I also put a little bit more engine oil on gears and everything else. Than...try to simulate the real conditions like the rear wheel is spining, put the wrench socket on the drill and try to spin the drive shaft (front spocket). While spining it, try to change the gears in the same time it should work. This scenario you can compare to manual transmission car, sometimes in car you can ‘t put in gear if the car is turned off and standing in one spot. My bike after 15 hours is running great.

[@FullPayGaming]

@@janjakus3596 I understabd you are explaining a metod you did to test yours, but what solved the issue? Was there an issue? Im going thru the exact same thing, can switch to all gears like he did. BUT I can spin the transmission smoothly regardless.NEED HELP. ANYONE?

[@bradleymadosh3596]

I have a YZ450F 2004 is there a washer that goes on Transmission next to bearing? On the right hand side of bike when sitting on it? I watched a video of a 4 wheeler engine being rebuilt and he said dont forgot this washer. Do the dirt bike have these? There wasn't any on it when i took it apart. The 5th gear was skipping when accelerating. Thank you great video also

[@jasontompkins4341]

How did ya manage to slid in the drum mechanism for the shift forks I’m struggling with mine

[@austinminer9614]

I fucking love you, thank you for your videos! Haha

[@sparkygarage2813]

Where did you get a new crank? Can't find one anywhere...

[@vloneblake7691]

MortorCycle ID or Parts Giant Bro

[@curtiswilcock5628]

I was stuggling ebay do some decent kits

[@paydirt347]

5:32 you say check if the small pin is in the shifting drum? Is that the Neutral Point spring? Ive put the case back together and cant work out where on the shift drum this spring goes. Any help? WR450 2012.

[@Ryan.fromWA]

Ever find this answer? Looking to start my rebuild on my 2011, will be my first

[@christophermccartney5833]

That's the neutral point pin, the small spring is sandwiched between the neutral point pin and the shift drum, it just sits down in the recess/hole. I worried about this too, but if you drop it down in it doesn't fall out the other side, it's designed to sit down in that hole.

[@juannnn8074]

Hola buen video una pregunta estoy buscando piston para yzf 426 modelo 2000 se ve si algún modelo de la yzf 450 le va?

[@marcosr5958]

por ebay puedes encargarlo

[@StarClashRoyale]

Hello, are the parts of wr426 and yz426 the same?

[@jasontompkins4341]

I believe so yes

[@jacopienaar9157]

hey do you might know how to convert a yz26f into a yz450f

[@wrenchmaster8889]

Yes, you have to change: cylinder, piston, crankshaft, timing chain, cylinder head (not sure for this one). and if you luckey the flywheel and crankshaft gears will fit. And then we haven't said anything about the year. In other words, ist to expensife and to big of a risk to do it.

[@loganlowe7290]

U can get a big bore kit which makes the 426 a 490 and u shouldn't have to change too much

[@christophermccartney5833]

@@wrenchmaster8889 I can answer for the 2003-2005 WR450F models (last of the steel frame generation), and the YZ and WR engines were the same except for:- lighter flywheel on YZ, different exhaust camshaft (same intake cam on both), same cylinder and pistons, wider gear ratios on WR (hence the name Wide Ratio 450 Four stroke), same carbs but different jetting, restricted throttle stop and airbox on WR, different timing on both (same timing chains though, YZ is advanced (or retarded) 1 tooth), no decompression cable on YZ. As far as engine differences that's pretty much it on the inside. This is a great video series and keep up the good work, I struggled with assembling the gearbox, very fiddly job, but it's done now. Thank you!

[@Ord750]

Too much silicone.